Method of manufacturing tubular articles



Aug. 26, 1930. w. MERRILL 1,773,924

METHOD OF MANUFACTURING TUBULAR ARTICLES Filed Jan. 50, 1929 v 2 72 1.Jg f INVENTOR Mun/Er MERRILL Patented nug.;2e,- 1930 UNITED; STATESWHITNEY MERRILL, oF nRooKLYn, NEW YORK METHQDOF MANUFACTURING TUBULARARTICLES Application filed January 30, 1929. ,Serial No. 336,284.

This invention relates in eneral to a meth od for manufacturing tubu ararticles and is concerned more particularly with an improved method formanufacturing the sock- 5 et member which constitutes an element ofcertain types of couplings used to connect tubular members or pipestogether.

It will be appreciated from the .descrip tion of the method hereinaftergiven that it is. readily adapted to; be usedin the manufacture oftubular articles other than coupling sockets but for convenience only,the method is described herein as applied to the manufacture ofsuchsockets.

during the erection or remodeling of buildings, observation towers,display racks and other structures of a similar nature are frequentlyconstructed of metallic tubular membars or pipes suitably connectedtogetherwhere theycross in horiz'ontaland vertical directions. As itwould be extremely impractical to employ tubular members whose lengthsequal the overall dimensions .of the scaffolding, for example, it iscustomary to connect convenient lengths of tubing a gether by couplings,an improved form of.

which is illustrated and described herein'for the' purpose of explainingthe present inventio 'Because of the large number of couplingsordinarily necessary, it is desirable that they 1 be of simpleconstruction, easily ap lied and cheap. The form of coupling descri edherein has been found to meet these requirements satisfactorily and itis the object of the present invention to describe an improved method ofmanufacturing the socket member of such a coupling whereby they maybe 40made more cheaply. i

Heretofore these coupling sockets were cast and then machined so as toaccommodate the coupling lug,which necessarily was an expensive and slowmethod.v .Accordih to the present invention these coupling soc etsScafioldings erected to support workmenof insertion of the end 2 in thetubular memare drop-forgedor similarly formed from a blank of; suitablematerial. But before describing the method of the present invention indetail, the construction ,of the coupling members will be described,reference being made to the accompanying drawing in which I Fig. 1 is apartial cross-sectional view of a preferred form of coupling plugshowing .a section of tubing connected thereto.

Fig. 2 is a partial cross-sectional view of .55 a preferred form ofcoupling socket showing a section of tubing connected thereto.

Fig. 3 is a right end view of the plug shown in Fig. 1.

Fig. 4is a left end view of the socket shown inFig.2.' Fig; 5 isacross-sectional yiew through a piece of tubing showing the relativepositions ofthe'plug and socket when two sections of tubing have beenconnected together by means of the coupling described herein.

Fig. 6 is an end view of the coupling socket in the process ofmanufacture after it has been punched but before it has been bent intotubular form, and i "Fig. 7 is a plan view thereof.

In the drawing the numeral 1 indicates a coupling plug of which one end2 is of relatively greater diameter than the other end and is adapted tofit snugly in the end of a section of tubing 3 as shown in Fig. 1. Thetubing may be, and preferably is, connected to the end 2 of'the plug bymeans of a plurality of depressions 4 therein which are forced intosuitable recesses 5 in the end 2 of the plu thus making a strong, rigidconnection etween' the coupling members and the pipe sections. The plug1 is provided with a fiange 6 as shown, to limit the depth her 3. Theend 7 of the plug 1 is of reduced diameter and is provided with twodiametrically opposite lugs 8 which project from the surfaceof theend 7as more clearly Shaw in Fig. 3.

illustrated in Figs. 2 and vided on the in position ther sions 11as'dcsci'i member 9'is prov a shoulder 18' tubular member .0 abinsertion of the coupli member. Two diam ing projections 14 are interiorsurface of the co bular opposite lockintegral on the ling head 12 as andare adapted to wedge against the lugs 8 on the coupling I lug 1 to holdthe coupling plug and coupling socket together. Clearance spaces 15between the locking projections 14 are made of sufficient width topermit the projections 8 onthe coupling plug to pass between theprojections 14. Helical surfaces 16' are proin ner surfaces of theprojections 14 as shown in Fig. 2, whereby upon rotation of the couplingsocket with respectto the coupling plug these two members are drawntogether longitudinally. The end of the coupling socket which extendsinto the tubular member 10 is of such thickness as to accommodate in therecesses formed therein the depressions 11 and has a central opening 17of such diameter that the end 7 of the coupling Y plug may be readilyinsertedtherein.

When desired to connect the tubular members 3 and 10 together after theyhave been connected to the plug 1 and socket 9, respectively, thecouplingplug 1 is inserted in the coupling socket 9 by aligning theiugs8' with tated with respect to the coupling plug that the lugs 8 arepositioned on the surfaces the spaces 15 so that the lugs may bepositioned to lie in back of the locking projections 14. Thereafter'thecoupling socket 9 is ro- 16 as indicated -more clearly in Fig. 5. Asdescribed above the helical surfaces 16 cause the coupling plug andcoupling socket to be brought together longitudinally and therelativepositions of the lugs .8 and projections 14 are such that whenthe socket has been rotated through a convenient angle, preferablyslightly in excess of 90 degrees, the end of the coupling head 12 willabut against the It will be observed that by these construe-5 tionsthetubular members 3 and 10 have been connectedtogether so that they cannotbe dis connected without rotating the one with respect to the other andthat the external surface of the head 12 of the coupling socket 9fastening means to and the flange 6 on the coupling plug 1 lie I flushwith the external surfaces of the tubular members, thus permittingclamps or other he placed over the tubing thereof are connected towheretwo sections gether. I

The method of making the coupling sockets according to the presentinvention may be deof which ise ping socket the c the circum erence Athe central portion of i from one edge of 19 of the blank from which thebee socket is formed as illustrated in The margins of the head portion19 and ti e portions 2% are offset from one another as indicated at 21in order to provide the finished socket with the enlarged head 12. Theupper end of the slot 18 is widened as shown at 22 to facilitate thebending of the blank as described below. I

The blank thus formed .is heated and then drop-forged or otherwisetreated so that the sections thereof on each side of the slot 18 and thecentral portion 23 are formed into the shapes required of them in thefinished socket. In the present instance this forging operationcomprises bending these sections into substantially semi-cylindical formand providing them with the locking projections 14 and with the recesses24 used in connecting the tubing to the socket.

After this forging operation the central portion 28 of the blank is bentto bring the sections thereof on each side of the portion 23 togetheruntil the substantially circular cross-section shown by the dotted linesin' Fig. 6 is produced.

As thisbending occurs wholly within the central portion 23 which, asshown in Fig. 6, is comparatively thin, a very great force is notnecessary and there is no danger of distor-ting the ad'acent sections ofthe blank. The blank increasesin thickness at the bevel surface 21 butas this surfacedoes not extend across the central portion 23 because ofthe enlarged opening 22, no additional bending force is required. I j

Althoughnot usually necessary, the margins of the slot 18 andthe outermargins of the blank which now lie close to eachother may be welded orotherwise united together. To protect the socket from corrosion andrust, it may be galvanized or otherwise protectivelytreated.

It will be apparent from the description that the method hereindescribed is not necessarily confined-to the manufacture of tubularsockets but, on the contrary, adapted to be used in the manufacture ofother articles of various cross sections which may or may not encloseadefinite area to form a tubular cross section. Thus, for example, thepresent method may be employed in the manufactureof channeled articlesor articles of sheet material having other nonhomaloidal cross sections.

is readily .gitudinal slot therein extending in from one end of saidblank, forming the sections of said blank on each side of the centerlinethere of into substantially semi-cylindrical shape having internalprojections forming locking members and then bending the material ofsaid blank between the end of said slot and the end of said blank toform the coupling socket.

3. The method of making hollow coupling sockets having an enlarged headportion at oneend from suitable material which comprises forming a'blankhaving a central lon- 'gitudinal' slot extending in from one end of saidblank to'the head portion material, the

material of said portion in alinement with said slot being made thinnerthan the adjacent material, forming the sections of said blank on eachside of said thinner section and said slot into substantiallysemi-cylindrical shape having internal projections on the head portionforming lopking members and then bending the material of said blankalong the said thinner section of the headvportion to formthe couplingsocket.

I 4. The method of making hollow articles, comprising'forming anintegral blank having two semi-cylindrical portions of the'same radiusconnected together along a 'line parallel to their axes and also havingtwo semi-cylindrical portions of the same radius which, however, issmaller than the radius of the first mentioned portions, the lattermentioned portions being respectively connected to the first mentionedportions, but separated frtm one another; and so bending the blank alongthe line connecting the first mentioned portions that the completedarticle comprises two cylindrical portions of different radii, theexterior of the portion having the larger radius being in the form of asmooth-surfaced cylin-f der.

5. The method of making hollow coupling sockets comprising forming anintegral blank having two semi-cylindrical portions of the same radiuswith internal projections forming locking members, said portions beingconnected together along a line parallel to their axes, and said blankalso having two semi-cylindrical portions of the same radius which,however, is smaller than the radius of the first mentioned portions,thelatter mentioned portions being respectively connected to the firstmentioned portions, but'separated from one another; and so bending theblank along the line connecting the first mentioned portions that thecompleted article comprises two cylindrical portions of different radii,the exterior of the portionhaving the larger radius being in the form ofa smooth-surfaced c linder. I

y WHITNEY MERRILL.

